Internal grinding machine



June 18, 1935. H. H. ASBRIDGE INTERNAL GRINDING MACHINE Filed July 5, 1954 Patented June 18, 1935 land, assignor to The Churchill Machine Tool Company Limited, Broadheath, England, a

British company Application July 3, 1934, Serial No. 733,676

.In Great Britain July 19, 1933 I 4 Claims.

This invention relates to internal grinding machines and particularly to the means employed. for imparting short and relatively rapid reciprocatory movements to-the work-table or 5 slide for the purpose of imparting a high degree of finish to the ground surface and to smooth out any irregularities in the finished surface which may be caused by the grinding wheel.

The object of my present invention is to provide improved means for imparting the said reciprocatory movements to a table which has been traversed by hydraulic means to the position in which grinding is performed upon the work-piece.

The invention comprises the combination with the hydraulic means by which the worktable is traversed to its stop or grinding position and with a stop limiting the movement of the table under the hydraulic pressure, of means imparting relatively rapid and short movements to the table through the stop against the hydraulic pressure which returns the table after each such movement.

The invention further comprises the mounting of the stop in an oscillatory carrier.

The invention further comprises the arrangement wherein the movement of the stop towards its operative position limits the rate of flow of the hydraulic fluid which is moving the table towards the stop.

The accompanying explanatory drawing illustrates one convenient application of my invention.

The work-table a which is traversed to its stop or service position (at which grinding is efiected) by a hydraulic ram 2), engages a stop 0 at the end of such traverse and is held against such stop by hydraulic pressure acting through the ram b. The stop is connected to means which cause it to impart short movements to the work-table against the hydraulic pressure which may be relieved by a loaded release valve at r, the hydraulic fluid returning the table when the stop so allows. The stop 0 may comprise a spring loaded slide 0 carried in a frame d capable of pivotal movement about a fulcrum e by a crank ,f and connecting rod 9 or other usual device. The stop 0 may be adapted to ride up an incline it upon a bracket 1' upon the work table a as the latter approaches the grinding position. The slide 0 has a part thereon which controls the hydraulic fluid supplied to the outer end of the ram cylinder by the pipe is so as to slow down the rate of movement of the ram and table before the latter is brought to rest against the stop 0, after which the table has relatively rapid and short reciprocations impartedthereto by the oscillation of the frame at and of the stop 0. i

The work-table a moves the work-piece mounted on the head a over the grinding wheel m which is then fed up to the internal surface of the work-piece to be ground in any suitable manner. The slide n carrying the grinding wheel head 0 does not move withthe table a as will be understood but is mounted'independently thereof. I

p is the driving pulley for the drive to the crank pin 1 and q is the driving pulley for the hydraulic pump 1' by which pressure fluid is supplied to the hydraulic cylinder b containing Q the mm b. The handle s controls the supply and exhaust of hydraulic fluid to and from the ends of the cylinder b It is shown in a position in which hydraulic'fluid is passing to the left hand end of the cylinder and is, being exhausted from the other end.

By the employment of my invention I simplify the means for improving the'finish of the workpiece.

What I claim is:

1. In an internal grinding machine, the combination of a grinding wheel, a slidable worktable, hydraulic means to traverse the worktable to its stop or grinding-position, astop limiting the movement df the table slidably mounted in a pivotally mounted carrier for pivotal movement in a plane parallel to the direction of movement of the Work-table, mechanical means to impart relatively rapid and short pivotal movements to said stop carrier, a cam track associated with said slidable work-table to depress said stop in its carrier as said table approaches its stop or grinding position, resilient means associated with said stop to resist such depression thereof, an abutment associated with said work-table adapted to be pressed continuously-against the said stop by the hydraulic traversing means when said table is in its stop or grinding position, and means actuated on depression of said stop to limit the flow. of hydraulic fluid to said hydraulic traversing means.

2., In an internal grinding machine having a tained pressed against a stop whilst grinding proceeds, the mounting of said stop upon a slide in a carrier pivoted about a fulcrum and oscil lated continuously about said fulcrum by mechanical power means in a plane parallel to the direction of movement of said work-table slide, means to depress said stop slide in its carrier as said work-table approaches its grinding position, and means for effecting the aforementioned slowing down of the-rate of hydraulictraverse of said work-table slide arranged for operation mechanically upon depression of said stop slide.

3. A grinding machine having a grinding wheel and a work-table, hydraulic means operating a slide to bring said grinding wheel and a workpiece mounted upon said work-table into working engagement, a stop to limit the travel of said slide, and means to produce small axial movements between wheel and workpiece duriing said working engagement; said stop being mounted slidably in a pivoted carrier, mechanical power means to oscillate said carrier about slide approaches the position in which the aforesaid working engagement takes place, spring means to resist such depression, and means for reducing the rate of action of said hydraulic means mechanically connected with said stop slide for actuation on depression thereof.

4. An internal grinding machine having a work-table, hydraulic means to traverse the work-table into the grinding position and to maintain it therein and means to cut down the rate of said traverse, a spring-loaded slide in a pivotally mounted carrier arranged to actuate said last named means on movement in said carrier against the resistance of said spring, a cam track moved with said work-table arranged to move said spring-loaded slide, mechanical means to oscillate said pivotally mounted carrier about its fulcrum and a stop upon said spring-loaded slide arranged to contact with an abutment movable with the work-table and by its movements to impart through said abutment to said table small and rapid movements against the pressure of said hydraulic traversing means.

HARRY HALES ASBRIDGE. 

